#include <iostream>
int main()
{
    std::cout<<"hi"<<std::endl;

    // pointer
    int val = 10;
    int *ptr = nullptr;
    ptr = &val;

    std::cout<< ptr <<std::endl;
    std::cout<< val <<std::endl;
    std::cout<< &val <<std::endl;
    std::cout<< *ptr <<std::endl;
    return 0;
};